PROJECT SUMMARY This renewal application seeks continued support for years 41-45 of the Washington University Training Program in Immunology. Washington University has made a strong and lasting commitment to Immunology research and training through the development of an Immunology Graduate Program, responsible for directing graduate education in Immunology and coordinating the Immunology-related activities of the 74 faculty, 150 postdoctoral fellows and 68 graduate students that constitute our Immunology community. The Immunology community at Washington University has achieved a world- recognized status, including 5 members of the National Academy of Science. It is characterized by a collaborative atmosphere that has helped establish an excellent environment for training young Immunologists. This grant and the Washington University Immunology Community have formed a symbiotic relationship where the growth of the community has been catalyzed through the benefits of trainee support afforded by this training grant, and the quality of our training program has been enhanced by the growth and interactive nature of the community. This program contains elements that ensure the appropriate training of Immunologists at both the predoctoral and postdoctoral levels. Fundamental laboratory research resides at the center of the training experience for both types of candidates. A total of 51 Immunology research faculty are listed on this grant but trainees can work with any of the 74 Immunologists at Washington University or even choose faculty as mentors that are not in immunology. In addition, all trainees participate in University-wide Immunology seminars, journal clubs, work-in-progress meetings and retreats. Predoctoral trainees must complete and show competence in a rigorous curriculum of basic training where they are exposed, through formalized classroom experiences, to historical, modern and emerging concepts of Immunology, related biomedical sciences and research ethics. Postdoctoral trainees are provided with a similar scientific training, but additionally, they are mentored/advised for careers in immunology and a separate ethics course. Of the 51 predoctoral students supported by this grant over the past 15 years, 96% continue in research, with 38% in academic careers. Of the 40 postdoctoral trainees supported over the past 15 years, 93% continue in research with 43% pursuing academic careers. To ensure continuity of this highly successful comprehensive Immunology training experience and to accommodate the number of outstanding trainees that need to be supported, we are requesting 6 predoctoral and 4 postdoctoral trainee slots. This successful Training Program is thus producing the next generation of basic and clinician scientists who will elucidate how the immune functions and who may go on to develop novel therapeutic strategies to prevent autoimmune disease and effective cancer immunotherapies.